AI - Practice on Spectrometric Methods - Part 1

What are the two common types of radiation used in spectrometric methods?

• Gamma rays and sound waves

• Electromagnetic radiation and ions/electrons

• Visible light and thermal radiation

• Ultrasonic waves and infrared radiation

What is the speed of electromagnetic radiation in a vacuum?

• 3.00 x 10^6 m/s

• 2.99 x 10^8 m/s

• 1.50 x 10^8 m/s

• 3.00 x 10^8 m/s

Which of the following is NOT a type of molecular energy state?

• Electronic states

• Vibrational states

• Rotational states

• Chemical states

What happens during the relaxation process after excitation?

• Molecules gain energy

• Molecules emit radiation

• Molecules freeze

• Molecules become ionized

What is the main difference between fluorescence and phosphorescence?

• Phosphorescence is short-lived

• Fluorescence involves a change in electron spin

• Fluorescence occurs without intersystem crossing

• Phosphorescence occurs in a metastable state

What is luminescence?

• Emission of sound waves

• Emission of radiation without energy absorption

• Emission of radiation after absorption of energy

• Absorption of energy without emission

Which type of radiation induces rotation in molecules?

• UV-VIS radiation

• Microwave radiation

• X-ray radiation

• Infrared radiation

What is the energy absorbed during excitation equal to?

• The kinetic energy of the molecule

• The potential energy of the molecule

• The energy difference between the states

• The total energy of the molecule

What is wavenumber and its unit?

• wavenumber = 1/wavelength [cm^-1]

• wavenumber = 1/frequency [cm^-1]

• wavenumber = 1/wavelength [s^-1]

• wavenumber = 1/velocity [s/m]

The essential components of spectrophotometer include:

• Light Source

• Monochromator

• cuvettes

• Photosensitive detector

• All the above